Eddy Dynamics Near Sharp Interfaces and in Straining Flows

Author(s):  
J. C. R. Hunt ◽  
I. Eames ◽  
J. Westerweel
2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Caihong Li ◽  
Juntong Zhu ◽  
Wen Du ◽  
Yixuan Huang ◽  
Hao Xu ◽  
...  

AbstractMonolayer transition metal dichalcogenides (TMDs) show promising potential for next-generation optoelectronics due to excellent light capturing and photodetection capabilities. Photodetectors, as important components of sensing, imaging and communication systems, are able to perceive and convert optical signals to electrical signals. Herein, the large-area and high-quality lateral monolayer MoS2/WS2 heterojunctions were synthesized via the one-step liquid-phase chemical vapor deposition approach. Systematic characterization measurements have verified good uniformity and sharp interfaces of the channel materials. As a result, the photodetectors enhanced by the photogating effect can deliver competitive performance, including responsivity of ~ 567.6 A/W and detectivity of ~ 7.17 × 1011 Jones. In addition, the 1/f noise obtained from the current power spectrum is not conductive to the development of photodetectors, which is considered as originating from charge carrier trapping/detrapping. Therefore, this work may contribute to efficient optoelectronic devices based on lateral monolayer TMD heterostructures.


2005 ◽  
Author(s):  
C.C. Ebbesmeyer ◽  
G.S. Rosenthal ◽  
K.A. Kurrus ◽  
C.A. Coomes
Keyword(s):  

1991 ◽  
Vol 238 ◽  
Author(s):  
Y. Huai ◽  
R. W. Cochrane ◽  
Y. Shi ◽  
H. E. Fischer ◽  
M. Sutton

ABSTRACTThe structures of equal-thickness Co/Re multilayer films and several Co/Re bilayer films have been investigated by X-ray diffraction at low and high angles. Analysis of low-angle reflectivity data from bilayer films indicates that interfacial intermixing is limited to three monolayers and that the two interfacial configurations are different. The high-angle X-ray diffraction data show that multilayer films have coherent interfaces and a highly textured structure with hep [002] orientations normal to the film plane for periods 21 Å ≤ Λ ≤220 Å. Detailed structures have been determined by fitting the X-ray spectra to calculated ones using a trapezoidal model. The results indicate that samples with 42 Å≤ Λ ≤220 Å have relatively sharp interfaces, in good agreement with the bilayer results. In addition, an out-of-plane expansion of the Co (002) layer is observed in samples with large Λ and results from structural disorder leading to a reduced atomic density. For Λ <21 Å the interfaces arise from the rougher surfaces of the deposited layers.


2004 ◽  
Vol 126 (3) ◽  
pp. 391-398 ◽  
Author(s):  
Brandon S. Field ◽  
Eric Loth

A downward blowing isothermal wall jet at moderate Reynolds numbers (1,500 to 8,500) with significant inflow turbulence (ca. 6%) was investigated. The flow configuration is an idealization of the air curtains of refrigerated display cases. Flow visualization using particle seeding was employed to identify the flow field eddy dynamics. Particle Image Velocimetry was used to examine the velocity fields in terms of mean and fluctuating values. These diagnostics showed that the air curtain entrainment was dominated by a large variety of eddies that engulfed ambient air into the air curtain. The velocity fields generally showed linear spreading, significant deceleration and high turbulence levels (ca. 25%). It was observed that the air curtain dynamics, velocity fields and growth were not significantly sensitive to Reynolds number variation between Re=3,800 and Re=8,500. However, at low air velocities (Re=1,500), the curtain was found to detach, leading to a large air curtain thickness and high curtain entrainment.


2001 ◽  
Vol 670 ◽  
Author(s):  
Ran Liu ◽  
Stefan Zollner ◽  
Peter Fejes ◽  
Rich Gregory ◽  
Shifeng Lu ◽  
...  

ABSTRACTRapid shrinking in device dimensions calls for replacement of SiO2 by new gate insulators in future generations of MOSFETs. Among many desirable properties, potential candidates must have a higher dielectric constant, low leakage current, and thermal stability against reaction or diffusion to ensure sharp interfaces with both the substrate Si and the gate metal (or poly-Si). Extensive characterization of such materials in thin-film form is crucial not only for selection of the alternative gate dielectrics and processes, but also for development of appropriate metrology of the high-k films on Si. This paper will report recent results on structural and compositional properties of thin film SrTiO3 and transition metal oxides (ZrO2and HfO2).


2021 ◽  
Author(s):  
Jan-Chi Yang ◽  
Ping-Chun Wu ◽  
Chia-Chun Wei ◽  
Qilan Zhong ◽  
Sheng-Zhu Ho ◽  
...  

Abstract Epitaxial growth is of significant importance over the past decades, given it has been the key process of modern technology for delivering high-quality thin films. For conventional heteroepitaxy, the selection of proper single crystal substrates not only facilitates the integration of different materials but also fulfills interface and strain engineering upon a wide spectrum of functionalities. Nevertheless, the lattice structures, regularity and crystalline orientation are determined once a specific substrate is chosen. In this work, we reveal the growth of twisted oxide lateral homostructures with multiple conjunction degree of freedom. The twisted lateral homostructures with atomically sharp interfaces can be composed of epitaxial “blocks” with different crystalline orientations, ferroic orders and phases. We further demonstrate that this approach is universal for fabricating various complex systems. Our results establish an efficient pathway towards twisted lateral homostructures, allowing epitaxial films to be arbitrarily tailored at designated positions with unbounded in-plane conjunction tunability.


Author(s):  
A. Fasano ◽  
M. Primicerio

Nanoscale ◽  
2018 ◽  
Vol 10 (45) ◽  
pp. 21062-21068 ◽  
Author(s):  
Xiaolong Zhang ◽  
Wipakorn Jevasuwan ◽  
Ken C. Pradel ◽  
Thiyagu Subramani ◽  
Toshiaki Takei ◽  
...  

p-Si/i-Ge core–shell and p-Si/i-Ge/p-Si core–double shell nanowires are fabricated using CVD with vapor–liquid–solid growth methods. Selective doping and sharp interfaces between the Si core and the Ge shell are achieved, which can provide a feasible design for realizing high electron (hole) mobility transistors.


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